<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <script src="../jsLib/angular-1.3.0.js"></script>
    <title></title>
</head>
<body ng-app ng-controller="control">
<input type="text" ng-model="aa">
<div >{{aa}}</div>
<script>
    var control = function($scope){
        $scope.aa="hello";
        $scope.$watch(function(){
            alert(1)
        })
    }
</script>
</body>
</html>